Can You Add Debt to Your Mortgage?

Last updated: 11 September 2026

What 'adding debt to your mortgage' actually means

People often talk about "adding" a credit card or loan to their mortgage, but that's not literally what happens. Your mortgage doesn't gain new line items for each debt. Instead, you increase the size of your mortgage, through a remortgage or a further advance, and the extra money raised is used to pay each debt off completely and directly, usually by your solicitor or your lender, rather than by you.

Once that happens, the original debts are gone, paid off in full, and what's left is a single, larger mortgage balance in their place. You've swapped several separate repayments, often at very different interest rates, for one additional slice of mortgage borrowing, usually at a lower rate than credit cards or unsecured loans charge, but repaid over a much longer period.

This is different from a secured loan, also called a homeowner loan or second charge mortgage, which is its own separate loan sitting behind your mortgage rather than merging into it. With a secured loan, your mortgage itself doesn't change size at all, you simply take on a second, independent payment alongside it.

The two ways to actually do this: remortgage or further advance

A remortgage means replacing your whole mortgage with a new, larger one, often with a different lender, and using the extra amount to clear your debts on completion. It resets your deal entirely, which is worth weighing against any early repayment charge on your current mortgage.

A further advance is different: you stay with your existing lender, and they simply lend you an additional amount on top of your current mortgage balance, often as a separate sub-account at their own rate for further borrowing. Your original mortgage rate on the rest of the balance usually stays untouched. Not every lender offers this, and some won't allow it specifically for debt consolidation, so it's worth checking rather than assuming it's available.

Both routes end with the same outcome: your unsecured debts are paid off directly, and your mortgage balance grows by roughly the same amount. The difference is mainly in process, cost and whether you keep your current lender.

What kinds of debt can be added this way

Most unsecured debt qualifies: credit cards, personal loans, overdrafts, store cards and catalogue debt are all routinely cleared this way. Car finance can sometimes be included too, though if it's secured against the car itself, your lender will want to understand the agreement before including it.

Debts that are already secured, such as an existing second charge mortgage on your home, are handled differently, since they involve another lender's charge on your property rather than a simple unsecured balance. If you have one of these alongside unsecured debt, a broker can talk through how both fit together.

Lenders also look at how many separate debts you're clearing and how long they've been open. A handful of credit cards and a personal loan, run up over a couple of years, is a very ordinary picture for this kind of application. What tends to prompt more questions is a large number of very recently opened accounts, or debt that's grown sharply in the last few months, since a lender will want to understand your current spending pattern before adding to your mortgage.

What the numbers look like

Here's a worked example using fixed, illustrative figures, not a live quote, showing how clearing debt this way can change your monthly outgoing.

	Amount
Current monthly payments (credit cards at 24.9% and a personal loan at 12.9%)	£465/month
New mortgage payment on the extra £19,000 borrowed (5.4% over 20 years)	£130/month
Total repayable on the extra £19,000 over the 20-year term	£31,200

The monthly figure falls considerably, which is the appeal for most homeowners. The trade-off is the total repaid over 20 years, which comes to more than the £19,000 originally cleared, because the debt is now being repaid over a much longer period than the original agreements would have run for.

The real cost: why 'making it disappear' isn't the whole story

It's tempting to think of this as making your debts disappear, and in one sense they do, the individual agreements are closed and gone. But the money still has to be repaid, now as part of your mortgage, typically over 15 to 25 years rather than the 2 to 7 years a credit card or personal loan might have run for.

That longer term is exactly why the monthly payment falls so much, and it's also why the total interest paid over the life of the borrowing can end up higher than if you'd kept paying the original debts off faster. Neither outcome is automatically right or wrong, it depends on whether the lower monthly payment now matters more to you than the total cost over time, and a broker should walk you through both sides before you decide.

How lenders decide whether to let you do this

Lenders look at your available equity, your income, your outgoings once the new payment is added, and your credit history. For a further advance, they'll also check that your existing mortgage payments are up to date. Checking your options with a broker first will not affect your credit score, so it's worth doing before you approach any lender directly.

They'll also want to see roughly what the extra borrowing is being used for, and debt consolidation is a purpose most mainstream and specialist lenders understand well. Some will ask for a breakdown of the debts you're clearing as part of the application, partly to confirm the amount you need and partly to make sure the new mortgage payment genuinely leaves you better off each month than your current combined payments do.